Ionic FormulasTurning chemistry into algebra

REVIEW• We can tell how many electrons an atom will

gain or lose by looking at its valence electrons.

• Metals like to lose electrons. (Cations)– Ex. Na +

• Nonmetals like to gain electrons. (Anions)– Ex: O 2-

• All elements try to have a full valence of 8 electrons(OCTET RULE).

Chemical Bonding

A chemical bond is the force of attraction that holds two atoms together.

Attractive Force

Na Cl

Why do elements form chemical bonds?

Atoms form chemical bonds in order to fill their outermost energy level with electrons.

• A full valence causes an atom to be more stable.•A full valence consists of 8 valence electrons.

Ionic Bonding

Ionic bonds: Metal atoms transfer electrons to nonmetal atoms. Producing oppositely charged ions (cation & anion) which attract each other.

Na + + Cl- NaCl

Write an ionic formula for Na+ bonding with F−

Balance the charges. Na+ F−

(1+) + (1-) = 0

1 Na+ and 1 F− = NaF

Write an ionic formula for K+ bonding with S2−

Balance the charges. K+ S2−

K+

2(1+) + (2-) = 0

2 K+ and 1 S2− = K2S

Write an ionic formula for Fe3+ bonding with OH−

Balance the charges.Fe3+ OH−

OH− OH−

(3+) + 3(1-) = 0

1 Fe3+ and 3 OH− = Fe(OH)3

Write the formula for…

an ionic compound composed of:

Al3+ and S2-

Al2S3

Write the formula for…

an ionic compound composed of:

Cd2+ and NO2-

Cd(NO2)2

Write the formula for…

an ionic compound composed of:

Ag+ and CO32-

Ag2CO3

Write the formula for…

an ionic compound composed of:

Pb2+ and NO3-

Pb(NO3)2

Write the formula for…

an ionic compound composed of:

Hg2+ and PO43-

Hg3(PO4)2

Naming Ionsand ionic formulas

Naming Cations

• Cation- if the charge is always the same (Group A) just write the name of the metal.

• Transition metals can have more than one charge, so indicate the charge with roman numerals in parentheses.

Name the following:Na+ Fe+2 Fe+3 Pb+2

Write formulas for the following:• Potassium ion• Copper (II) ion• Barium ion• Mercury (II) ion

Naming Cations

Naming Anions

• Anions are always the same, change the element ending to – ide

• F-1 Fluorine

Naming Anions

• Anions are always the same, change the element ending to – ide

• F-1 Fluoride

Name the following:

Cl- N-3 Br- O-2

Write formulas for the following:• sulfide ion• iodide ion• phosphide ion• fluoride ion

Naming Anions

Naming Ionic Compounds

• Cation + Anion.• To write the names just name

the two ions.• NaCl = Na+ Cl- = sodium chloride• MgBr2 = Mg+2 Br- = magnesium

bromide

• Write the name of CuO• Need the charge of Cu, O is -2• copper must be +2• Copper (II) oxide

Naming Ionic Compounds

Write the names of the following• KCl• Na3N• PbO• PbO2

Naming Ionic Compounds